The CBLK-300-3 from Crystek Corporation is a DC Block with Frequency 300 KHz to 3 GHz, Insertion Loss 0.02 to 0.4 dB, Breakdown Voltage 16 V, Return Loss 14 to 51 dB, Operating Temperature -55 to 90 Degree C. Tags: Connectorized, Inner DC Block. More details for CBLK-300-3 can be seen below.